Printed books and journals continue to be popular consumer items and research tools, despite their relative inefficiency as a means for locating data. Electronic tools that permit scanning a hard drive or the World Wide Web for a single keyword or complex Boolean search request cannot, due to the nature of the medium, determine if the desired text is present in a printed book. Even the index of a printed book does not enable a reader to efficiently perform a simple multi-term search, unless the person who prepared the index had closely anticipated the reader's particular search. Performing a search in multiple printed books, for instance twenty books of similar subject matter grouped together on a library shelf, is a time-consuming task using the tools of the current art. Nevertheless, books and journals printed on paper are in broad use for many reasons unrelated to ease of data access, including consumers' preferences for reading from printed books and the publishing industry's recognition of the greater likelihood of public adherence to copyright laws if the medium is printed rather than electronic.
Various methods and devices are known in the art for text searching of electronically stored media. For example, U.S. Pat. No. 5,640,552 to Yianilos, whose disclosure is incorporated herein by reference, describes a device which provides text recovery from electronically stored text. There are no known devices, however, that enable rapid, efficient searching of text in a printed medium.